Open Paleo

Altirhinus

Norman, 1998 al-ti-RIEN-us /ˌæltɪˈraɪnəs/

From Latin 'altus' meaning 'high' and Greek 'rhinos' meaning 'nose', meaning 'high nose', referring to its distinctively arched nasal profile.

113.2–100.5 million years ago Albian, Early Cretaceous
Early Cretaceous stages

Altirhinus is a genus of ornithopod dinosaur from the Early Cretaceous (Albian) Khuren Dukh Formation of Dornogov, Mongolia. The only known species, Altirhinus kurzanovi, is characterized by its distinctive highly arched nasal region.

Diagnosis

  1. Rostral tip of nasals strongly arched, giving the snout a distinctively elevated profile.
  2. Lateral flaring of premaxilla to widen the oral cavity not bounded by a raised rim; rostral portion of premaxilla downcurved.
  3. Carpus well ossified but not co-ossified into two discrete blocks as in Camptosaurus, Iguanodon, and Ouranosaurus.
  4. Shaft of ischium straight, parallel-sided and with an axial twist.
  5. Large, finger-shaped lesser trochanter not flattened and appressed to the anterolateral margin of the greater trochanter.
  6. Two replacement crowns in deeper (caudal) portions of both maxillary and dentary dentitions.

Species

Altirhinus kurzanovi Norman, 1998

Type species

Named for Sergei Kurzanov, the influential Russian paleontologist who originally found the specimens in 1981.

Holotype
PIN 3386/8 , Paleontological Institute, Russian Academy of Sciences
Material
Much of the left side of the skull; right side skull isolated bones; left and right atlas neural arches; scapula, coracoid, sternals, pubis, ischia, manus digit V, ungual of manus IV and III, three pedal phalanges including one ungual.
Horizon
Khuren Dukh Formation, Albian, Early Cretaceous , 113.2–100.5 million years ago
Locality
Khuren Dukh, Dundgovi, Mongolia

References

  1. Norman, D. B. (1998). On Asian ornithopods (Dinosauria: Ornithischia). 3. A new species of iguanodontid dinosaur. Zoological Journal of the Linnean Society 122(1-2): 291-348. Oxford University Press (OUP). doi:10.1111/j.1096-3642.1998.tb02533.x

    Erected Altirhinus and regarded it as a derived iguanodontid alongside Iguanodon and Ouranosaurus, treating its hadrosaurid-like cranial features as convergent.

    norman1998a
  2. Godefroit, P.; Escuillié, F.; Bolotsky, Y. L.; Lauters, P. (2012). A new basal hadrosauroid dinosaur from the Upper Cretaceous of Kazakhstan. Bernissart Dinosaurs and Early Cretaceous Terrestrial Ecosystems (Godefroit, P., ed.) 334-358. Indiana University Press, Bloomington.

    Recovered Altirhinus among the successive Asian grade of non-hadrosaurid hadrosauroids.

    godefroit2012a
  3. Poole, K. E. (2022). Phylogeny of iguanodontian dinosaurs and the evolution of quadrupedality. Palaeontologia Electronica 25(3): a30. doi:10.26879/702

    Recovered Altirhinus within Hadrosauroidea in its iguanodontian phylogeny.

    poole2022a
  4. Norman, D. B. (2014). Iguanodonts from the Wealden of England: do they contribute to the discussion concerning hadrosaur origins?. Hadrosaurs 10-43. Indiana University Press, Bloomington.

    Recovers Altirhinus in an unresolved neoiguanodontian plexus in its unordered analysis; the ordered analysis and summary cladogram place it closer to hadrosaurids than to Iguanodon.

    norman2014b
  5. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a